FIG. 7.

hom6Δ mutation confers sensitivity to FK506. (A) Approximately 10⁷ cells from hom6Δ mutant strain MAY308 were plated on solid YPD medium and exposed to 250 μg of FK506 diffusing from a paper disk. A control paper disk containing only the FK506 solvent (90% EtOH plus 10% Tween 20) was included. The plate was incubated at 30°C for 2 days and photographed. As a control, the same assay was conducted with isogenic wild-type strain BY4742. (B) Liquid YPD cultures of hom6 (MAY308) and wild-type (BY4742) strains were exposed to 10 μg of FK506/ml or left untreated as controls, and growth was measured based on optical density at 600 nm (OD₆₀₀). (C) hom6Δ cells from the FK506-exposed culture described for panel B were photographed using differential interference contrast microscopy after 22 h of incubation with the drug.